docs: clarify uninstall run-order + statusLine ceiling (#278)

Follow-up to #228 (issue #226):

- README: state that scripts/uninstall.js must run *before* the host
  remove command, since the script is itself a plugin file and gets
  deleted by the removal (or run it from a separate clone).
- uninstall.js: add a ponytail: comment naming the statusLine match
  ceiling — substring match + whole-key delete removes a combined
  (e.g. caveman+ponytail) statusline wholesale; upgrade path noted.
- Add trailing newline to the file.

Co-authored-by: Claude Opus 4.8 <noreply@anthropic.com>

Author: DietrichGebert

README.md

@@ -219,7 +219,7 @@ Which files map to which agent: [Agent portability](docs/agent-portability.md).
 | Pi agent | `pi uninstall ponytail` |
 | Cursor / Windsurf / Cline / etc. | Delete the copied rule file |
 
-These remove the plugin's own files. They leave behind a small amount of state ponytail writes outside the plugin folder: the mode flag, `~/.config/ponytail/config.json`, and (if you accepted the setup nudge) a `statusLine` entry in `~/.claude/settings.json`. Run `node scripts/uninstall.js` (from this repo, or wherever it was installed) to clean those up too. It only removes the statusLine entry if it points at ponytail's own script, so a statusline you set up yourself is left untouched.
+These remove the plugin's own files. They leave behind a small amount of state ponytail writes outside the plugin folder: the mode flag, `~/.config/ponytail/config.json`, and (if you accepted the setup nudge) a `statusLine` entry in `~/.claude/settings.json`. Run `node scripts/uninstall.js` to clean those up too. **Run it before the host remove command above** — the script is itself a plugin file, so removing the plugin first deletes it (or run it from a separate clone of this repo). It only removes the statusLine entry if it points at ponytail's own script, so a statusline you set up yourself is left untouched.
 
 ## Commands
 

scripts/uninstall.js

@@ -26,11 +26,15 @@ try {
   const raw = fs.readFileSync(settingsPath, 'utf8').replace(/^\uFEFF/, '');
   const settings = JSON.parse(raw);
   const cmd = settings.statusLine && settings.statusLine.command;
+  // ponytail: substring-match the script name, then drop the whole statusLine
+  // key. A combined statusline (e.g. caveman+ponytail) whose command contains
+  // "ponytail-statusline" gets removed wholesale. Parse out only ponytail's part
+  // if combined statuslines become common.
   if (typeof cmd === 'string' && cmd.includes('ponytail-statusline')) {
     delete settings.statusLine;
     fs.writeFileSync(settingsPath, JSON.stringify(settings, null, 2), 'utf8');
     console.log(`Removed ponytail statusLine entry from ${settingsPath}`);
   }
 } catch (e) {
   if (e.code !== 'ENOENT') throw e;
-}
+}